Up to now, 2-, 3-, 4- and ω-alkenoic acids and lower esters thereof have been known as flavoring materials.
The present inventors, on the other hand, have been proposed that a 5-alkenoic acid (see Japanese Unexamined Patent Application Publication No. 58-96014) and a trans-6-alkenoic acid (see Japanese Examined Patent Application Publication No. 1-40877) are useful as flavoring materials and that a 5-alkenoic acid butyl ester and/or a 6-alkenoic acid butyl ester (see Japanese Examined Patent Application Publication No. 6-14846) have a milk-like flavor.
The inventors have made intensive and extensive studies for developing another flavoring materials for dairy products. As a result, the inventors have found that a mixture of a 5-alkenoic acid and/or 6-alkenoic acid and a lower aliphatic aldehyde is a good flavoring material, and have accomplished the invention.